Complexity of deciding conjugacy of rational relations
The conjugacy problem for rational relations can be stated as follows: A rational relation defined by a letter-to-letter finite state transducer , that is, a finite state automaton whose transitions are labeled by pairs of letters (rather than by single letters). Is it true that for every accepting run of , the concatenation of the first components of the labels is a of the concatenation of the second components? That is, does there exist such that: 1) for all , and 2) for all . This problem is known to be decidable (see by C. Aiswarya, Amaldev Manuel, and Saina Sunny). However, the known decision procedure relies on describing the rational relation using a form of regular expressions. Is there a more efficient algorithm that works on the finite state transducer, without converting it into a regular expression?
